[Rtk-users] Lateral blur in a FDK reconstructed volume

[Vincent Libertiaux]

Hello rtk users !

I am facing a problem for which I have exhausted all the possibilities 
except asking you.
I have performed a standard FDK reconstruction of a lego bricks 
assembly.  I used a custom-made code to compute the detector horizontal 
offset and tilt angle, found to be 1.15 mm and 0.02° respectively.  The 
result of the reconstruction is shown in the picture 
https://ibb.co/LdMzJF2 .  The volume looks mostly sharp, except on the 
lateral edges, let's say on the last half brick.

We had the opportunity to have the same volume reconstructed with two 
commercial solutions.  The first one, "A", produced the same results 
than rtk.  The second, "B", produced the result shown in the picture 
https://ibb.co/VwXMmRH

In this case, the edges are sharp too.  The offset values found with 
this software were very close (1.13mm and 0.025° respectively) and 
feeding them to rtksimulatedgeometry didn't change my result.  No other 
correction was allegedly applied.

I thought that the edge blurring was due to a wobbling artefact but it 
can't be the case according to the result with the "B" software.

Do you have any idea on what could cause this blurring on the edges ?

I thank you very much for any clue.

Best regards,

Vincent